A shoe outsole structure including two resin materials that have different rigidities and are integral with each other has been known from Patent Document 1, for example.
Specifically, Patent Document 1 discloses a shoe sole including spikes and formed by integrating a first resin and a second resin which is higher in Young's modulus than the first resin together. The first resin is provided to correspond to a region continuous from the metatarsophalangeal joints (the so-called MP joints) to the tiptoe of a forefoot. The second resin includes a first band portion having the shape of a band and extending along the hallux located at the medial side of a foot, and a second band portion having the shape of a band and extending along the fifth toe located at the lateral side of the foot. The first band portion extends to correspond to a region from a rear end of the forefoot to a site of the proximal condyle of the proximal phalanx of the hallux. On the other hand, the second band portion extends to correspond to a region from the rear end of the forefoot to a site of the proximal condyle of the proximal phalanx of the fifth toe.